IC chip tester with heating element for preventing condensation

ABSTRACT

An IC chip testing apparatus provided with an IC socket  206  to which an IC chip is brought into electrical contact, a printed circuit board  205  with one terminal which is electrically connected to a terminal of a test head and with another terminal which is electrically connected to a terminal of the IC socket  206 , and a heating element  208  provided at the printed circuit board  205 . The IC chip testing apparatus may be provided with a socket  320  to which an IC chip to be tested is detachably mounted; a socket guide  382  holding the socket  320 ; a chamber  306  to the opening  392  of which the socket guide  382  is attached so that an IC chip mounting opening of the socket  320  faces inside the chamber and able to maintain the inside at a predetermined state less than ordinary temperature; a printed circuit board  400  which is electrically connected to a terminal of the socket  320  and which is arranged at the outside of the chamber opening  392  of the chamber  6 ; and a heating board  406  which is provided around the chamber opening  392  of the chamber  306  and heats the printed circuit board  400  by heat conduction. It is possible to prevent condensation of the printed circuit board which tends to occur at the time of application of a low temperature and radiation of heat from the IC socket which tends to occur at the time of application of a high temperature or low temperature.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an electronic device testingapparatus for testing semiconductor integrated circuit devices(hereinafter abbreviated as “ICs”) and other electronic devices, moreparticularly relates to an electronic device testing apparatus able toprevent condensation on the printed circuit board easily occurringduring the application of a low temperature and the radiation of heatfrom a socket easily occurring during the application of a hightemperature or low temperature.

[0003] 2. Description of the Related Art

[0004] A handler of an IC chip testing apparatus or other electronicdevice testing apparatus conveys a large number of IC chips held on atray into it, brings them into electrical contact with a test head in astate with a high temperature or low temperature thermal stress applied,and has them tested at the IC testing apparatus. When the tests arecompleted, the IC chips are conveyed out from the test head and reloadedon trays in accordance with the results of the test so as to sort theminto categories such as good chips and defective chips.

[0005] The handlers of the related art may be roughly classified by typeof application of temperature into chamber type handlers which reload ICchips to be tested on a special tray called a “test tray”, convey itinto a temperature application chamber to bring the IC chips to apredetermined temperature, then push the IC chips against the test headin the state loaded on the test tray and heat plate type handlers whichload IC chips on a heat plate (also called a “hot plate”) to apply ahigh temperature thermal stress to them, then pick up a several numberof the IC chips at a time by suction heads and convey them to the testhead against which they are then pushed.

[0006] In both types of handlers, the test head against which an IC chipis pushed is provided with an IC socket having contact pins and one ormore printed circuit boards (mother board, daughter boards, sub-boards,etc.) electrically connected to the IC socket. The printed circuitboards are connected to input-output terminals of the test head. The ICchip is tested by the testing apparatus through the test head.

[0007] When applying a high temperature or low temperature thermalstress in a chamber type handler, however, while the IC chip is given ahigh temperature or low temperature in the chamber, when the IC chip isbrought into contact with the IC socket, the heat is dissipated fromthere and therefore the problem arises of a fluctuation in the appliedtemperature during the tests. In particular, in a test head of a typedirectly connected to the IC socket and mother board and other printedcircuit boards, the heat conducted to the IC socket is easily radiatedto the printed circuit boards. When applying a low temperature thermalstress, further, condensation occurs at the printed circuit boards andtherefore there was a danger of a detrimental effect on the signalcharacteristics.

[0008] Also in a heat plate type handler, while the IC chip is given ahigh temperature, when the IC chip is brought into contact with the ICsocket, the heat is dissipated from there and therefore the problemarises of a fluctuation in the applied temperature during the tests inthe same way.

[0009] Also in a test head of a type where a spacing frame is arrangedbetween the IC socket and thee print circuit board, when the IC chip isgiven an extremely low temperature stress of about −50° C., the lowtemperature conducts through the coaxial cable and the daughter boardconnecting the IC socket and the print circuit board and therefore thereis a danger that condensation occurs at the printed circuit boards.

[0010] Further, in a testing apparatus testing an IC chip inside achamber in this way, since the chip mounting opening of the socket inwhich the IC chip is mounted faces inside the chamber and the terminalsof the socket are connected to the test head through a printed circuitboard outside the chamber (performance board), the structure is onesusceptible to entry of outside air behind the socket. Therefore, thereis the problem of a susceptibility to condensation at the printedcircuit board behind the socket or the test head. If condensed moistureflows to electrical contact portions, there is the danger of causingshort-circuits at the electrical wiring. Therefore, condensation must beprevented at all costs.

[0011] Accordingly, in the testing apparatuss of the related art, alarge distance was set between the socket and the printed circuit boardsand a spacing frame or other heat insulating structure was arrangedbetween them to prevent condensation at the printed circuit boardsbehind the socket and the test head.

[0012] If a large distance is set between the socket and the printedcircuit boards in this way, however, the electrical path from the socketto the printed circuit boards (electrical cables etc.) becomes longerand noise more easily occurs, so the reliability of the tests is liableto drop. Further, it is not possible to use general purpose printedcircuit board holding rings and other parts and it is necessary toprepare special spacing frames and other heat insulating structures, sothe manufacturing costs rise.

SUMMARY OF THE INVENTION

[0013] A first object of the present invention is to provide anelectronic device testing apparatus which can prevent the condensationat the printed circuit boards which easily occurs at the time ofapplication of a low temperature and the radiation of heat from thesocket which easily occurs at the time of application of a hightemperature or low temperature.

[0014] A second object of the present invention is to provide anelectronic device testing apparatus which can, by a relativelyinexpensive structure, effectively prevent the occurrence ofcondensation behind a socket where an electronic device is mounted fortesting.

[0015] To achieve the first object of the present invention, accordingto a first aspect of the present invention, there is provided anelectronic device testing apparatus comprising a socket to which anelectronic device is brought into electrical contact, a circuit boardwith one terminal which is electrically connected to a terminal of atest head and with another terminal which is electrically connected to aterminal of the socket, and a heating element provided at the circuitboard.

[0016] The heating element is preferably printed on the circuit board.

[0017] The printed circuit board is preferably provided in proximity tothe socket.

[0018] In the electronic device testing apparatus of the first aspect ofthe present invention, since the printed circuit board is provided witha heating element, it is possible to heat the printed circuit board inaccordance with the temperature to be applied so as to reduce thetemperature gradient between the electronic device and the printedcircuit board and therefore suppress radiation of heat from the socketto the printed circuit board. Further, since the heating element alsoserves as an auxiliary means for application of a high temperature, itis possible to shorten the time for raising the temperature and possibleto expect an improvement in the throughput of the electronic devicetesting apparatus. On the other hand, by heating the printed circuitboard at the time of application of a low temperature, it is possible toprevent condensation from occurring at the printed circuit board.

[0019] In the present invention, the heating element is not particularlylimited in where it is provided, but should at least be provided aroundthe socket when applying a high temperature. This is since it issufficient to keep heat from being conducted to the printed circuitboard through the socket. As opposed to this, when applying a lowtemperature, it is desirable to provide the heating elementsubstantially across the entire area of the printed circuit board. Thisis because condensation occurs when the ambient temperature drops andsuch condensation must be prevented across the entire area of theprinted circuit board.

[0020] In the electronic device testing apparatus of the first aspect ofthe present invention, the method of provision of the heating element isnot particularly limited. A heating unit may be mounted on the printedcircuit board or the heating element may be printed on the printedcircuit board. As the method of printing the heating element on theprinted circuit board, the method of forming a pattern by etching, themethod of printing planar nichrome wiring, etc. may be mentioned. Byprinting the heating element on the printed circuit board, interferenceetc. with other components connected on the printed circuit board iseliminated and the printed circuit board can be placed even in narrowspaces.

[0021] In the electronic device testing apparatus of the first aspect ofthe present invention, the relative arrangement of the socket and theprinted circuit board is not particularly limited. The invention may beapplied to not only a test head of the type where the socket issubstantially directly connected to the printed circuit board, but alsoa test head of the type where the socket is connected to the printedcircuit board through a socket board, spacing frame, etc. In particular,as explained above, the effect of prevention of radiation of heat andprevention of condensation becomes greater when the printed circuitboard is provided in proximity to the socket.

[0022] To achieve the second object of the present invention, accordingto a second aspect of the present invention, there is provided anelectronic device testing apparatus comprising a socket to which anelectronic device to be tested is detachably mounted; a socket guideholding the socket; a chamber to the opening of which said socket guideis attached so that an electronic device mounting opening of the socketfaces inside the chamber and able to maintain the inside at apredetermined state less than ordinary temperature; a circuit boardwhich is electrically connected to a terminal of the socket and which isarranged at the outside of the chamber opening of the chamber; and aheating board which is provided around the chamber opening of thechamber and heats the printed circuit board by heat conduction.

[0023] In the present invention, the heating board is not particularlylimited, but preferably is a board containing a rubber heater or otherplanar heating element. Further, the electronic device tested by thetesting apparatus of the present invention is not particularly limited,but an IC chip is shown as a preferable example.

[0024] The heating board is preferably provided around the chamberopening of the chamber through a mounting base.

[0025] The socket guide is preferably detachably mounted to the mountingbase.

[0026] The circuit board preferably contacts the heating board through acircuit board holding ring so as to form a first air-tight space at thecircuit board side of the socket guide. Note that in the presentinvention, the “air-tight space” is not necessarily a completelyair-tight space and may also communicate with the outside through somespace. An air-tightness of an extent enabling a dry gas to be sealed inthe space is sufficient.

[0027] A first seal member is preferably interposed at the portion ofcontact of the circuit board holding ring and the heating board.

[0028] A second seal member is preferably interposed at the portion ofcontact of the circuit board and the circuit board holding ring.

[0029] At the anti-chamber side of the circuit board is preferablyattached a reinforcing plate so as to form a second air-tight space withthe circuit board and the reinforcing plate is preferably provided witha drying nozzle for feeding dry gas into the second air-tight space.Note that as the dry gas, dry air is preferable.

[0030] Preferably, the circuit board is electrically connected through aplurality of movable pins on a movable pin holding ring projecting outin a ring-shape from a test head sending test drive signals to theelectronic device mounted at the socket, the reinforcing plate isprovided at the inside of the movable pin holding ring, and the secondair-tight space formed between the circuit board and the reinforcingplate is made air-tight by a seal ring provided at the inside of themovable pin holding ring.

[0031] The circuit board may be brought in contact with the heatingboard through a seal member so as to form a first air-tight space at thecircuit board side of the socket guide.

[0032] The heating board is preferably formed with a drying passage forfeeding dry gas into the first air-tight space.

[0033] In the electronic device testing apparatus according to thesecond aspect of the present invention, since a heating board isprovided around the chamber opening of the chamber with an inside cooledto a temperature less than ordinary temperature and the printed circuitboard is heated by heat conduction, the printed circuit board positionedbehind the socket is heated to a temperature above the dew point of theambient gas. Therefore, it is possible to effectively prevent theoccurrence of condensation at the printed circuit board behind thesocket and the test head.

[0034] Further, in the electronic device testing apparatus according tothe second aspect of the present invention, since no special spacingframe or other heat insulating structure is employed, it is possible touse general purpose printed circuit board holding rings and other partsand the manufacturing costs become lower. Further, since it is no longernecessary to separate the printed circuit board and the socket by morethan the necessary amount of distance, the electrical path from thesocket to the printed circuit board (electrical cables etc.) can beshortened, greater resistance to noise can be obtained, and thereliability of the tests can be improved.

[0035] Further, in the present invention, by bringing the printedcircuit board into contact with the heating board through a printedcircuit board holding ring so as to form a first air-tight space at theprinted circuit board side of the socket guide and forming in theheating board a drying passage for feeding dry gas in the firstair-tight space, the first air-tight space can be filled with a dry gas.This enables condensation behind the socket guide to be furthereffectively prevented.

[0036] Further, in the present invention, by attaching a reinforcingplate at the anti-chamber side of the printed circuit board so as toform a second air-tight space with the printed circuit board andattaching to the reinforcing plate a drying nozzle for feeding dry gasinto the second air-tight space, the second air-tight space can also befilled with a dry gas. This enables condensation behind the printedcircuit board as well to be further effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] These and other objects and features of the present inventionwill become more apparent from the following description of thepreferred embodiments given with reference to the attached drawings, inwhich:

[0038]FIG. 1 is a plan view of an IC chip testing apparatus according toa first embodiment of the present invention;

[0039]FIG. 2 is a sectional view along the line II-II of FIG. 1;

[0040]FIG. 3 is a sectional view showing details of a contact section ofa test head of FIG. 2;

[0041]FIG. 4 is a plan view of a socket guide of FIG. 3;

[0042]FIG. 5 is plan view of a performance board of FIG. 3;

[0043]FIG. 6 is a sectional view along the line VI-VI of FIG. 5;

[0044]FIG. 7 is a plan view of a performance board of an IC chip testingapparatus according to another embodiment of the present invention;

[0045]FIG. 8 is a sectional view of a test head of an IC chip testingapparatus according to another embodiment of the present invention;

[0046]FIG. 9 is a sectional view of a test head of an IC chip testingapparatus according to still another embodiment of the presentinvention;

[0047]FIG. 10 is a schematic overall view of an IC chip testingapparatus according to a first embodiment of the present invention;

[0048]FIG. 11 is a sectional view of key parts of the IC chip testingapparatus;

[0049]FIG. 12 is a sectional view of key parts showing the state beforeattachment of the socket guide shown in FIG. 11 to the chamber side; and

[0050]FIG. 13 is a sectional view of key parts of the IC chip testingapparatus according to another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] Preferred embodiments of the present invention will be discussedin detail below:

[0052] First Embodiment

[0053] As shown in FIG. 1, the IC chip tester apparatus 1 correspondingto the electronic device tester apparatus of the present embodiment iscomprised of a handler 10, test head 20, and tester 30. The test head 20and the tester 30 are connected via a cable 40. The pre-test IC chipscarried on a feed tray 102 of the handler 10 are pushed against thecontact sections of the test head 20 by X-Y conveyors 104, 105, the ICchips are tested through the test head 20 and the cable 40, and then theIC chips finished being tested are placed onto sorting trays 103 inaccordance with the results of the tests.

[0054] The handler 10 is provided with a board 109. On the board 109 areprovided conveyors 104, 105 for the IC chips to be tested, explainedlater. The board 109 further is formed with an opening 110. As shown inFIG. 2, IC chips are pushed against contact sections 201 of the testhead 20 arranged behind the handler 10 through this opening 110.

[0055] The board 109 of the handler 10 is provided with two X-Yconveyors 104, 105. Among these, the X-Y conveyor 104 is configured tobe able to move a movable head 104 c from a region of the sorting trays103 to feed trays 102, empty trays 101, the heat plate 106, and twobuffer sections 108, 108 by rails 104 a, 104 b provided along itsX-direction and Y-direction. Further, the movable head 104 c is designedto be able to be moved in the Z-direction (that is, the verticaldirection) by a not shown Z-axial actuator. Two IC chips to be testedcan be picked up, conveyed, and released at one time by two suctionheads 104 d provided at the movable head 104 c.

[0056] As opposed to this, the X-Y conveyor 105 is configured to be ableto move a movable head 105 c between the two buffer sections 108, 108and the test head 20 by rails 105 a, 105 b provided along itsX-direction and Y-direction. Further, the movable head 105 c is designedto be able to be moved in the Z-direction (that is, the verticaldirection) by a not shown Z-axial actuator. Two IC chips can be pickedup, conveyed, and released at one time by two suction heads 105 dprovided at the movable head 105 c.

[0057] The two buffer sections 108, 108 move back and forth between theoperating regions of the two X-Y conveyors 104, 105 by the rails 108 aand not shown actuators. The buffer section 108 at the top in the figureworks to convey IC chips conveyed from the heat plate 106 to the testhead 20, while the buffer section 108 at the bottom works to eject theIC chips finished being tested at the test head 20. The provision ofthese two buffer sections 108, 108 enables the two X-Y conveyors 104,105 to operate simultaneously without interfering with each other.

[0058] In the operating region of the X-Y conveyor 104 are provided afeed tray 102 on which IC chips to be tested are loaded, four sortingtrays 103 on which tested ICs are stored sorted into categoriesaccording to the test results, and an empty tray 101. Further, a heatplate 106 is provided at a position in proximity to the buffer section108.

[0059] The heat plate 106 is for example a metal plate and is formedwith a plurality of indentations into which IC chips are dropped.Pre-test IC chips from the feed tray 102 are transferred to theindentations 106 a by the X-Y conveyor 104. The heat plate 106 is a heatsource for applying a predetermined thermal stress to the IC chips. TheIC chips are heated to a predetermined temperature by the heat plate106, then pushed against the contact sections of the test head 20through one of the buffer sections 108.

[0060] The top (contact sections 201) of the test head 20 according tothe present embodiment, as shown in FIG. 3, is provided with frog rings202 electrically connected to the test head 20 through cables 203. Eachof the frog rings 202 has a plurality of pogo pins 204 (contact pinshaving movable pins supported to be able to advance and retract in theaxial direction by springs and biased in a direction where the movablepins project out by the springs) provided facing upward in a ring. Aperformance board 205 is provided with terminals contacting the pogopins 204. Further, two IC sockets 206, 206 are mounted to the top of theperformance board 205 (corresponding to the printed circuit boardaccording to the present invention) in an electrically connected state.Due to this, the contact pins (not shown) of the IC sockets 206 areelectrically connected to the test head 20 body through the performanceboard 205, pogo pins 204, frog rings 202, and cables 203.

[0061] Note that each of the two IC sockets 206 has fitted into it asocket guide 207 having an opening 207 a and guide pins 207 b as shownin FIG. 4 and that an IC chip held by a suction head 105 d is pushedagainst an IC socket 206 through the opening of the socket guide 207. Atthis time, the guide pins 207 b provided at the socket guide 207 areinserted into the guide holes 105 d 1 formed in the suction head 105 d,whereby the IC chip and IC socket 206 are positioned with respect toeach other.

[0062] In particular, the performance board 205 according to the presentembodiment, as shown in FIG. 5 and FIG. 6, is provided with a heatingelement 208 in the area around where an IC socket 206 or socket guide207 is attached. The heating element 208, as shown in FIG. 6, may beformed as any layer in the multiple layer structure of the printedcircuit board comprising the performance board 205. In the figure, aheating element layer 208 is formed at the top surface of theperformance board 205 and ground layers 208 a, 208 a are formed aboveand below it. By providing the ground layers 208 a, it is possible tosuppress noise from occurring from the heating element layer 208. Theground layers 208 a, however, are not essential to the presentinvention.

[0063] The heating element layer 208 may be provided at the performanceboard 205 comprised of a printed circuit board by forming a pattern ofthe heating element by etching and also by forming nichrome wiringplanarly or other methods of mounting heating elements. Whatever thecase, wiring for carrying a current becomes necessary, so in the exampleshown in FIG. 5, a power supply wiring 208 b is formed to the edge ofthe performance board 205 and a connector 208 c is formed there. Thespecific technique is not limited in any way. Other means may also beemployed.

[0064] Further, in the present embodiment, a temperature sensor 209 isprovided at any location in the area where the heating element 208 isprovided so as to manage the temperature of the heating element 208. Byincorporating the temperature information from the temperature sensor209, problems such as overheating or underheating are prevented. Thecontrol of the temperature of the heating element 208, however, does nothave to be precise. Rough control to the extent of controlling thesupply of the power to the heating element 208 is sufficient. At thistime, the power may be supplied by the inverter method so as to preventnoise from the heating element 208.

[0065] Next, the operation will be explained.

[0066] A pre-test IC chip carried on the feed tray 102 of the handler 10is picked up and held by the X-Y conveyor 104 and transferred to anindentation 106 a of the heat plate 106. By leaving it there for exactlya predetermined time, the IC chip rises to a predetermined temperature.Therefore, the X-Y conveyor 104 transferring the not yet heated IC chipfrom the feed tray 102 to the heat plate 106 releases the IC, then picksup and holds an IC chip which had been left at the heat plate 106 andhad been raised to the predetermined temperature and transfers it to abuffer section 108.

[0067] The buffer section 108 to which the IC chip has been transferredmoves to the right end of the rail 108 a, is picked up and held by theX-Y conveyor 105, and, as shown in FIG. 3, is pushed against an ICsocket 206 of the test head 20 through the opening 110 of the board 109.

[0068] At this time, the heat of the now high temperature IC chip isconducted to the ordinary temperature IC socket 206 and starts to beradiated to the performance board 205 as well, but since the performanceboard 205 of the present embodiment is provided with the heating element208 and the area around the IC socket is heated to a suitabletemperature, the temperature gradient between the IC chip and theperformance board 205 becomes smaller and the amount of heat radiated tothe IC socket 205 is suppressed. Therefore, it is possible to test theIC chip at the initially desired temperature and improve the reliabilityof the test results.

[0069] Further, since a drop in the temperature of the IC chip issuppressed by the heating element 208 provided at the performance board205, it is possible to set the heating temperature at the heat plate 106low and it is thereby possible to expect a shortening of the time forraising the temperature, that is, improve the throughput of the IC chiptesting apparatus 1.

[0070] Second Embodiment

[0071] In the above embodiment, the explanation was given using as anexample an IC chip testing apparatus 1 applying a high temperaturethermal stress to the IC chip, but the electronic device testingapparatus of the present invention may also be applied to one applying alow temperature thermal stress. FIG. 7 is a plan view (plan viewcorresponding to FIG. 5) of a performance board according to anotherembodiment of the IC chip testing apparatus of the present invention.

[0072] In this embodiment, the IC chip testing apparatus is one whichapplies a low temperature thermal stress to the IC chip, then pushes itagainst an IC socket of the test head and executes the tests. Liquidnitrogen or another low temperature gas is supplied to a region normallynear the contact section 201 of the test head 20. In particular, asshown in FIG. 7, the performance board 205 of this embodiment isprovided with a heating element 208 over substantially its entire area.The invention is not limited to this, but the heating element 208 of thepresent embodiment is designed to prevent condensation on theperformance board 205, so it is preferable to provide the heatingelement 208 in the region where the electronic device is provided andnot only the area around the IC socket 206.

[0073] The structure of the contact section 201 of the test head 20 ofthe present embodiment is basically the same as that of the embodimentshown in FIG. 3, so will be explained with reference to that figure, butsince the IC chip is allowed to stand in this low temperature atmosphereso that the IC chip will fall to the predetermined temperature, this ispushed against an IC socket 206 of the test head 20 for the test.

[0074] At this time, the heat of the now low temperature IC chip isconducted to the performance board 205 through the IC socket 206,whereby the air near the surface of the performance board 205 is cooledand condensation starts, but since the performance board 205 of thepresent embodiment is provided with the heating element 208 andsubstantially the entire performance board 205 is heated to a suitabletemperature, it is possible to prevent the occurrence of condensation.

[0075] Further, the IC chip testing apparatus of the present inventionis particularly effective for a test head 20 provided with the ICsockets 206 and performance board 205 in close proximity as in theembodiment shown in FIG. 3, but does not exclude a test head 20 of atype such as shown for example in FIG. 8 or FIG. 9.

[0076] In the test head 20 shown in FIG. 8, the performance board 205(corresponding to printed circuit board of the present invention) ismounted above the test head body 20 a. A spacing frame 211 is providedabove the performance board 205 via spacer columns 210 able to movevertically somewhat in the Z-direction.

[0077] A socket board 213 is provided above the spacing frame 211through socket board spacers 212. IC sockets 214 are provided on thissocket board 213. The performance board 205 and the socket board 213 areconnected by a plurality of coaxial cables 215.

[0078] As opposed to this, in the test head 20 shown in FIG. 9, aperformance board 205 is attached above the test head body 20 a. Adevice specific adapter (DSA) performance board 216 (corresponding tothe printed circuit board of the present invention) is provided abovethe performance board 205 through spacer columns 210 able to movevertically somewhat in the Z-direction. A spacing frame 211 is providedfurther above this, while a socket board 213 is provided through socketboard spacers 212. Further, the DSA performance board 216 and socketboard 213 are connected by connector boards 217, while the DSAperformance board 216 and base board 209 are connected by a connector218 and coaxial cables 215.

[0079] Even in IC chip testing apparatuss provided with such test heads20, by provision of the heating elements 208 shown in FIG. 5 to FIG. 7at the performance board 205 shown in FIG. 8 and the DSA performanceboard 216 shown in FIG. 9 (even plus the performance board 205), asimilar action and effect as in the above embodiment can be exhibited.

[0080] Third Embodiment

[0081] As shown in FIG. 10, the IC chip testing apparatus 302 accordingto this embodiment is one which tests, as devices to be tested, IC chipsin the state of ordinary temperature, low temperature, or hightemperature and is provided with a handler 304 and a not shown test usemain unit. The handler 304 successively conveys IC chips to be tested toIC sockets provided on the test head and stores the IC chips finishedbeing tested on predetermined trays sorted in accordance with the testresults.

[0082] In this embodiment, the handler 304 is provided with a chamber306. The top of the test head 310 is exposed at a test stage 308 in thechamber 306. The top of the test head 310 is shown in FIG. 11. Sockets320 are mounted at the top of the test head 310. The chip mountingopenings of the sockets 320 face the inside of the chamber 306 so thatIC chips 322 conveyed by the suction heads 324 can be successivelydetachably mounted.

[0083] The IC sockets 320 provided at the test head 310 are connected tothe test use main unit (not shown) through cables. The IC chips 322detachably mounted at the IC sockets 320 are connected to the test usemain unit through cables and the IC chips 322 are tested by test signalsfrom the test main unit. The relation among the IC sockets 320 andchamber 306 and the test head 310 will be explained later in detail.

[0084] As shown in FIG. 10, the handler 304 has an IC magazine 330 forstoring IC chips to be tested and storing tested IC chips sorted intoclasses. The IC magazine 330 holds loader use trays 332A on which ICchips to be tested are carried, sorting trays 332B to 332E on whichtested IC chips are carried sorted into classes, empty trays 332F, andoption trays 332G. These trays 332A to 332G are arranged atpredetermined intervals along the X-direction and are stacked in theZ-direction (height direction).

[0085] IC chips carried on a loader tray 332A are conveyed to a soakstage 336 inside the chamber 306 using the first XY-conveyor 334attached to the handler 304. Further, IC chips finished being tested atthe test head 310 are finally loaded and sorted on the sorting trays332B to 332E of the IC magazine 330 using the second XY-conveyor 335.Among the sorting trays 332B to 332E, for example, the tray 332C is thetray for good devices, while the other trays are the trays for thedefective devices or devices for retesting.

[0086] The empty trays 332F are conveyed to and stacked over the sortingtrays 332B to 332E which have become filled with the tested IC chips andare used as sorting trays. The option trays 332G are used for otherapplications.

[0087] The inside of the chamber 306 is of an air-tight structure exceptfor the portion for the transfer of IC chips which is designed to beable to open and close by a shutter etc. For example, it can maintain ahigh temperature state of room temperature to about 160° C. or a lowtemperature state of room temperature to about −60° C. The inside of thechamber 306 is divided into a soak stage 336, a test stage 308, and anexit stage 340.

[0088] The soak stage 336 has a turntable 338 arranged in it. Thesurface of the turntable 338 has indentations 342 for temporarilyholding IC chips arranged at a predetermined pitch along thecircumferential direction. In the present embodiment, there are twoindentations 343 formed in the radial direction of the turntable 338.The two indentations 342 are arranged at a predetermined pitch in theradial direction. The turntable 338 turns clockwise. The IC chipsdropped into the indentations 342 of the turntable 338 at the loadingposition 344 by the first XY-conveyor 334 are given a thermal stressuntil the temperature conditions to be tested are reached while theturntable 338 is being indexed in the direction of rotation.

[0089] At a takeout position 346 about 240 degrees in the direction ofrotation from the loading position 344 based on the center of rotationof the turntable 338, the suction heads attached to one of the threecontact arms 348 are positioned above the turntable 338. At thatposition, IC chips can be taken out from the indentations 342 by thesuction heads. The three contact arms 348 are attached at angles ofsubstantially equal amount in the circumferential direction with respectto the shaft 350 and can be indexed 120 degrees at a time in theclockwise direction of rotation about the shaft 350. Note that this“index” means to repeatedly turn by a predetermined angle, then stop,then again turn by a predetermined angle. At the time of this indexingof a contact arm 348, the time when the arm 348 is stopped correspondsto the time during which IC chips are mounted in sockets of the testhead 310 and tested plus the time for attachment or detachment of the ICchips to or from the sockets. The stopping time of this indexing is thesame as the stopping time of the indexing at the turntable 338. Theturntable 338 and the contact arms 348 are indexed synchronously.

[0090] In the embodiment, the suction heads of one of the three contactarms 348 are positioned above the takeout position 346 of the soak stage336, the suction heads of another of the contact arms 348 are positionedabove the contact heads 310 of the test stage 308, and the suction headsof the other of the contact arms 348 are positioned above the inlet 352of the exit stage 340.

[0091] The IC chips loaded in the indentations 342 of the turntable 338at the loading position 344 of the turntable 338 are given apredetermined thermal stress while being indexed from the loadingposition 344 to the takeout position 346 and are picked up by thesuction heads of a contact arm 348 at the takeout position 346. The ICchips picked up by the suction heads are positioned above the test head310 by the indexing of the contact arm 348 in the clockwise direction.At that position, as shown in FIG. 11, the IC chips 322 picked up andheld by the suction heads 324 are attached to the sockets 320 andtested.

[0092] The IC chips 322 attached to the sockets 320 above the test head310 and finished being tested are picked up again by the suction heads324 and positioned above the inlet 352 of the exit stage 340 by theindexing of the contact arm 348 shown in FIG. 10 in the clockwisedirection. At this position, the tested IC chips are slid to the exitposition 354 by an exit shifter in the direction of the arrow A. At theexit position of the exit stage 340, the IC chips arranged above theexit shifter are returned from the temperature of the test, that is, thelow temperature or the high temperature, to ordinary temperature. In thecase of a low temperature test, the IC chips are returned to ordinarytemperature at the exit stage 340 so it is possible to effectivelyprevent condensation from occurring on the IC chips directly after beingtaken out from the chamber 306.

[0093] The IC chips arranged above the exit shifter at the exit position354 of the exit stage 340 are returned to ordinary temperature, thenshifted in the direction of the arrow B by a not shown exit arm andmoved to an exit turn arranged at the receiving position 356. The exitturn is designed to be able to move back and forth between the receivingposition 356 and the eject position 358 by turning in the direction ofthe arrow C. The suction heads of the second XY-conveyor 335 aredesigned to be able to move to the eject position 358 of the exit turn.The tested IC chips arranged at the eject position by the exit turn areconveyed by the conveyor 335 to one of the sorting trays 332B to 332Ebased on the test results.

[0094] In the device testing apparatus 302 according to the presentembodiment, a soak stage heat exchanger 360 is arranged at the ceilingof the soak stage 336 inside the chamber 306 of the handler 304 and atest stage heat exchanger 362 is arranged at the side wall of the teststage 308. These heat exchangers 360 and 362 are provided with coolingunits using liquid nitrogen etc. as a coolant and blowers forcirculating the cold air inside the chamber when the testing apparatus302 is able to perform low temperature tests. When the testing apparatus302 is able to perform high temperature tests, the heat exchangers 360and 362 are provided with heating units and blowers. When the testingapparatus is able to perform low temperature tests and high temperaturetests, the heat exchangers 360 and 362 are provided with cooling units,heating units, and blowers and are used switching between the coolingunits and heating units. These heat exchangers 360 and 362 arecontrolled by a temperature controller 370. The temperature controller370 receives as input output signals from a temperature sensor 372arranged at the test stage 308, temperature sensor 374 arranged at thesoak stage 336, and other sensors and can control the amount of heatexchange (output) of the heat exchangers 360 and 362 in accordance withthe output signals from these sensors.

[0095] In the following explanation, the explanation will be given ofthe case where the testing apparatus 302 is one able to perform bothhigh temperature tests and low temperature tests and the testingapparatus is used mostly for performing low temperature tests. As shownin FIG. 11 and FIG. 12, at the test stage 308, the bottom of the chamber306 comprised of a heat insulating material etc. and the main base 380holding the chamber 306 are partially cut away and sockets 320 held onthe test head 310 fit there.

[0096] The sockets 320 are held by socket guides 382. Each of the socketguides 382, as shown in FIG. 12, has a plurality of guide holes 384. Theguide holes 384 are designed to have inserted into them guide rods 386affixed to the chamber 306 side for positioning with the chamber 306.

[0097] The guide rods 386 are attached to a base ring 388. The base ring388 is affixed to a mounting base 390 and constitutes the chamberopening 392. The mounting base 390 has a heat insulating propertysimilar to that of the chamber 306 and is affixed detachably to thebottom opening of the chamber 306 and the main base 380.

[0098] As shown in FIG. 11, the socket guide 382 has a plurality ofguide pins 394 attached to it projecting out toward the inside of thechamber 306. The guide pins 394 are inserted into the guide holes 396 ofthe guide plate 395 attached to a suction head 324 for positioning ofthe IC chip 322 picked up and held by a suction head 324 and the socket320.

[0099] Behind the socket 320 (outside of chamber) is connected a lowtemperature use socket adapter 398 which is electrically connected tothe terminals of the socket 320. The adapter 398 is affixed to thesurface of the substantial center of the printed circuit board 400 andfacilitates the electrical connection of the terminals of the socket 320and the printed circuit board 400. At the bottom surface of the printedcircuit board 400 are electrically connected a plurality of movable pins404 on a movable pin holding ring 402 projecting out in a ring shapefrom the test head 310. The movable pins 404 are attached to the movablepin holding ring 402 facing upward and are also called pogo pins(contact pins having movable pins supported to be able to advance andretract in the axial direction by springs and biased in a directionwhere the movable pins project out by the springs). They are pushedagainst the bottom terminals of the printed circuit board 400 forelectrical connection with the printed circuit board 400. Note that theprinted circuit board 400 is also called a performance board.

[0100] The test head 310 receives drive signals from the test use mainunit, not shown, and sends test drive signals to the IC chip 322attached to the socket 320 through the movable pin holding ring 402,movable pins 404, printed circuit board 400, and adapter 398.

[0101] In the present embodiment, as shown in FIG. 11 and FIG. 12, aheating board 406 having an opening at its center is bolted etc. to thebottom surface of the mounting base 390. The heating board 406 is alsocalled an HIFIX heater and comprised of a rubber heater or other planarheating element 408 sandwiched between aluminum sheets etc. At thebottom surface of the heating board 406 is affixed in advance a firstseal member 412. The first seal member 412 is configured for example asa silicone sponge rubber sheet or other sheet having elasticity. The topsurface of the printed circuit board holding ring 414 detachablycontacts the bottom surface of the inner circumference side of theheating board 406 through the first seal member 412 which seals thespace between them. Further, the second seal member 416 is attachedbetween the printed circuit board holding ring 414 and the printedcircuit board 400 and seals the space between them. The second sealmember 416 is comprised of a synthetic resin sheet the same as ordifferent from that of the first seal member 412.

[0102] As a result of the sealing by the first seal member 412 and thesecond seal member 416, a first air-tight space 418 is formed at theprinted circuit board side of the socket guide 382. This first air-tightspace 418 has communicated with it a radial drying passage 410 formed inthe heating board 406. Dry gas can be filled into the first air-tightspace 418 from there. As the dry gas for being filled inside the firstair-tight space 418, for example dry air having a condensationtemperature lower than the temperature inside the chamber 306 may beused. For example, when the inside of the chamber 306 is about −55° C.,the condensation temperature of the dry air sealed inside the firstair-tight space 418 through the drying passage 410 is preferably about−60° C. The temperature of the dry air is for example about roomtemperature.

[0103] As shown in FIG. 11 and FIG. 12, the printed circuit boardholding ring 414 is arranged at a position corresponding to the positionof the movable pins 404 contacting the bottom terminals of the printedcircuit board 400. The top surface of the holding ring 414 contacts thebottom surface of the heating board 406 to push the printed circuitboard 400 downward and secure the electrical contact with the movablepins 404 and printed circuit board 400.

[0104] A reinforcing plate 420 is attached to the bottom surface of thecenter portion of the printed circuit board 400 (anti-chamber side)through a plurality of spacers 422. The reinforcing plate 420 is forpreventing the printed circuit board 400 from bending and is positionedinside of the movable pin holding ring 402. A second air-tight space 424is formed between the reinforcing plate 420 and the printed circuitboard 400 by attaching a ring-shaped third seal member 426 between theouter circumference of the reinforcing plate 420 and the innercircumference of the movable pin holding ring 402. This third sealmember 426 is comprised of a ring of a synthetic resin the same as ordifferent from the first seal member and seals the space between thereinforcing plate 420 and the printed circuit board 400.

[0105] The reinforcing plate 420 has a drying nozzle 460 attached to itfor feeding dry gas into the second air-tight space 424. As the dry gasto be introduced inside the second air-tight space 424, use may be madeof dry air with a condensation temperature somewhat higher than the dryair introduced inside the first air-tight space 418, for example, about−40° C. The temperature of the dry air is about the room temperature.The condensation temperature of the dry air introduced inside the secondair-tight space 424 may somewhat higher than the condensationtemperature of the dry air introduced inside the first air-tight space418 because the second air-tight space 424 is further away from theinside of the chamber 306 than the first air-tight space 418 and has alower possibility of condensation.

[0106] Note that a space 430 is also formed between the seal ring 428attached to the outer circumference of the socket adaptor 398 and theprinted circuit board 400, but since the dry air inside the secondair-tight space 424 is introduced into this space 430 through throughholes formed in the printed circuit board 400, it is also possible toeffectively prevent condensation at that portion.

[0107] In the electronic device testing apparatus 302 of the presentembodiment, a heating board 406 is attached around the chamber opening392 of the chamber 306 with an inside cooled to a temperature belowordinary temperature and the printed circuit board 400 is heated by heatconduction through the printed circuit board holding ring 414.Therefore, it is possible to effectively prevent condensation fromoccurring at the printed circuit board 400 behind the socket and thetest head 310.

[0108] Further, in the IC chip testing apparatus 302 according to thepresent embodiment, since a special spacing frame or other heatinsulating structure is not employed, it is possible to use generalpurpose printed circuit board holding rings 414 and other parts and themanufacturing costs become lower. Further, since it is no longernecessary to separate the printed circuit board 400 and the socket 320by more than the necessary amount of distance, the electrical path fromthe sockets 320 to the printed circuit board 400 (electrical cablesetc.) can be shortened, greater resistance to noise can be obtained, andthe reliability of the tests can be improved.

[0109] Further, in the IC chip testing apparatus 302 according to thisembodiment, by bringing the printed circuit board 400 into contact withthe heating board 406 through a printed circuit board holding ring 414so as to form a first air-tight space 418 at the printed circuit boardside of the socket guide 382 and forming in the heating board 406 adrying passage 410 for feeding dry gas in the first air-tight space 418,the first air-tight space 418 can be filled with a dry gas. This enablescondensation behind the socket guide 382 to be further effectivelyprevented.

[0110] Further, in the IC chip testing apparatus 302 of the presentembodiment, by attaching a reinforcing plate 420 at the anti-chamberside of the printed circuit board 400 so as to form a second air-tightspace 424 with the printed circuit board 400 and attaching to thereinforcing plate 420 a drying nozzle 460 for feeding dry gas into thesecond air-tight space 424, the second air-tight space 424 can also befilled with a dry gas. This enables condensation behind the printedcircuit board 400 as well to be further effectively prevented.

[0111] Fourth Embodiment

[0112] As shown in FIG. 13, the test stage 308 a of the testingapparatus according to this embodiment is configured so that the printedcircuit board 400 a constituting the test board is directly heated bythe heating board 406. Below, only the points of difference from thetesting apparatus according to the first embodiment will be explained.The explanation of common portions will be partially omitted.

[0113] The center of the mounting base 390 a affixed to the bottomopening of the chamber 306 has attached to it a base ring 388 a andforms the chamber opening 392 a. A socket guide 382 a is bolted etc. tothe base ring 388 a so that the socket 320 is positioned at the centerof the chamber opening 392 a.

[0114] Behind the mounting base 390 a (outside of chamber) is boltedetc. a heating board 406 having an opening at its center through amounting plate 450 serving also as a heating insulating member and asealing member. The heating board 406 is also called an HIFIX heater andis comprised of a rubber heater or other planar heating element 408sandwiched between aluminum sheets. The bottom surface of the heatingboard 406 has a first seal member 412 attached to it in advance. Thefirst seal member 412 is comprised for example of a silicone spongerubber sheet or other sheet having elasticity.

[0115] In the present embodiment, when connecting and affixing to thesocket 320 the socket adapter 398 a attached to the substantial centerof the printed circuit board 400 a serving as the test board, thesurface of the outer circumference of the printed circuit board 400 acomes into direct contact with the bottom of the heating board 406through the first seal member 412 and the printed circuit board 400 a isdirectly heated by the heating board 406.

[0116] The heating board 406 is formed with a radial drying passage 410.Dry gas can be filled into the first air-tight space 418 a formedbetween the socket guide 382 a and the printed circuit board 400 a. Asthe dry gas for being filled inside the first air-tight space 418 a, forexample dry air having a condensation temperature lower than thetemperature inside the chamber 306 may be used. For example, when theinside of the chamber 306 is about −55° C., the condensation temperatureof the dry air sealed inside the first air-tight space 418 a through thedrying passage 410 is preferably about −60° C. The temperature of thedry air is for example about room temperature.

[0117] In the electronic device testing apparatus according to thisembodiment, a heating board 406 is attached around the chamber opening392 a of the chamber 306 with an inside cooled to a temperature belowordinary temperature and the printed circuit board 400 a is heateddirectly by heat conduction. Therefore, the printed circuit board 400 apositioned behind the socket 320 is heated to a temperature above thedew point of the ambient gas. Therefore, it is possible to effectivelyprevent condensation from occurring at the printed circuit board 400 abehind the socket.

[0118] Further, in the IC chip testing apparatus according to thepresent embodiment, since a special spacing frame or other heatinsulating structure is not employed, the manufacturing costs becomelower. Further, since the distance between the printed circuit board 400a and the sockets 320 becomes remarkably short, the electrical path fromthe sockets 320 to the printed circuit board 400 a (electrical cablesetc.) can be shortened, greater resistance to noise can be obtained, andthe reliability of the tests can be improved.

[0119] Further, in the IC chip testing apparatus according to thisembodiment, by bringing the printed circuit board 400 a into contactwith the heating board 406 so as to form a first air-tight space 418 aat the printed circuit board side of the socket guide 382 and forming inthe heating board 406 a drying passage 410 for feeding dry gas in thefirst air-tight space 418 a, the first air-tight space 418 a can befilled with a dry gas. This enables condensation behind the socket guide382 to be further effectively prevented.

[0120] Other Embodiments

[0121] Note that the present invention is not limited to the aboveembodiments and can be changed in various ways within the scope of theinvention.

[0122] For example, in the third and fourth embodiments, the explanationwas mainly given of the case of conducting low temperature tests insidethe chamber 306 shown in FIG. 10, but the present invention can also beapplied even when conducting ordinary temperature tests inside thechamber 6. Further, the testing apparatus 2 shown in FIG. 10 is of atype enabling both ordinary temperature tests and high temperature testsas well in the chamber 6, but the testing apparatus according to thepresent invention can also be applied to a testing apparatus conductingonly low temperature tests or a testing apparatus conducting onlyordinary temperature tests. Further, in the testing apparatus accordingto the present invention, the method of handling the IC chips in thehandler 4 is not limited to the illustrated embodiments.

1. An electronic device testing apparatus comprising: a socket to whichan electronic device is brought into electrical contact, a circuit boardwith one terminal which is electrically connected to a terminal of atest head and with another terminal which is electrically connected to aterminal of the socket, and a heating element provided at the circuitboard.
 2. The electronic device testing apparatus as set forth in claim1, wherein the heating element is on the circuit board.
 3. Theelectronic device testing apparatus as set forth in claim 1, wherein theprinted circuit board is provided in proximity to the socket.
 4. Anelectronic device testing apparatus comprising: a socket to which anelectronic device to be tested is detachably mounted; a socket guideholding the socket; a chamber to the opening of which said socket guideis attached so that an electronic device mounting opening of the socketfaces inside the chamber and able to maintain the inside at apredetermined state less than ordinary temperature; a circuit boardwhich is electrically connected to a terminal of the socket and which isarranged at the outside of the chamber opening of the chamber; and aheating board which is provided around the chamber opening of thechamber and heats the circuit board by heat conduction.
 5. Theelectronic device testing apparatus as set forth in claim 4, wherein theheating board is attached around the chamber opening of the chamberthrough a mounting base.
 6. The electronic device testing apparatus asset forth in claim 5, wherein the socket guide is detachably attached tothe mounting base.
 7. The electronic device testing apparatus as setforth in claim 4, wherein the circuit board contacts the heating boardthrough a circuit board holding ring so as to form a first air-tightspace at the circuit board side of the socket guide.
 8. The electronicdevice testing apparatus as set forth in claim 7, wherein a first sealmember is interposed at the portion of contact of the circuit boardholding ring and the heating board.
 9. The electronic device testingapparatus as set forth in claim 7, wherein a second seal member isinterposed at the portion of contact of the circuit board and thecircuit board holding ring.
 10. The electronic device testing apparatusas set forth in claim 4, wherein at the anti-chamber side of the circuitboard is attached a reinforcing plate so as to form a second air-tightspace with the circuit board and the reinforcing plate is provided witha drying nozzle for feeding dry gas into the second air-tight space. 11.The electronic device testing apparatus as set forth in claim 10,wherein the circuit board is electrically connected through a pluralityof movable pins on a movable pin holding ring projecting out in aring-shape from a test head sending test drive signals to the electronicdevice mounted at the socket, the reinforcing plate is provided at theinside of the movable pin holding ring, and the second air-tight spaceformed between the circuit board and the reinforcing plate is madeair-tight by a seal ring provided at the inside of the movable pinholding ring.
 12. The electronic device testing apparatus as set forthin claim 4, wherein the circuit board is brought in contact with theheating board through a seal member so as to form a first air-tightspace at the circuit board side of the socket guide.
 13. The electronicdevice testing apparatus as set forth in claim 7, wherein the heatingboard is formed with a drying passage for feeding dry gas into the firstair-tight space.